Successful rehab? I don't know about that. According to Ken's website:

"Rodgers had been released from jail just four hours before hitting
Ken. He had been held for 12 hours on charges of DUI (Driving Under the
Influence) and a violation of the open container law. He has been
charged with murder."

The guy had only been release FOUR hours before he killed Ken after
sitting in jail for a DUI violation!

How did Jimmy Don "screw up" his chances for early parole?